Method and system for ensuring reliability of unicast video streaming at a video streaming platform

ABSTRACT

A method implemented in an electronic device serving as a stream distributor distributing unicast video and audio streams of a streaming platform system is disclosed. The stream distributor receives a unicast data flow containing data of a video and audio stream from a load balancer, the unicast data flow being transmitted in user datagram protocol (UDP) packets. The method includes the electronic device detecting initiation of a maintenance activity on a virtual machine or its host associated with the stream distributor. The method includes the electronic device indicating a failure mode of the stream distributor, where the failure mode indication is to cause the load balancer to switch the unicast data flow to an alternate stream distributor. The method also includes the electronic device detecting a completion of the load balancer switching the unicast data flow to the alternate stream distributor, and halting the distribution of the unicast data flow.

RELATED APPLICATIONS

This application is related to co-pending U.S. application No. not yetassigned, Attorney docket No. 8954P004, entitled “A Method and Systemfor A Graph Based Video Streaming Platform,” and co-pending U.S.application No. not yet assigned, Attorney docket No. 8954P005, entitled“A Method and System for Coordinating Stream Processing at A VideoStreaming Platform,” both filed herewith, which are incorporated hereinby reference.

FIELD OF INVENTION

The embodiments of the invention are related to the field of deliveringmedia contents over a network cloud. More specifically, the embodimentsof the invention relate to methods and systems for supporting a videostreaming platform in a cloud computing environment.

BACKGROUND

Cloud computing is changing the way that enterprises and consumersutilize applications and carrying on their tasks. In cloud computing,data and applications are stored over the Internet instead of localstorage, and instead of owning all the hardware and software that dataand applications reside, an enterprise or a consumer (the “client” or“tenant”) utilizes some or majority of the needed hardware and softwareowned by a cloud provider to store the data and run the applications.Relying on sharing of resources among numerous clients, the cloudcomputing infrastructure (sometimes referred to as Infrastructure as aservice (IaaS)) satisfies elastic demand spikes and achieves economiesof scale thus becoming popular in various industries.

Efficient media content (e.g., video/audio) processing via cloud-hostedservices has the potential of revolutionize the entertainment industry,sports industry and other related domains. Yet, it is challenging toprocess media contents (e.g., video/audio) efficiently and flexibly in acloud computing environment, especially in real time streamingscenarios. In an IaaS model, computing resources are often offered as anumber of virtual machines to a client requesting delivery of the mediacontent, and a hypervisor manages the offered virtual machines. Thevirtual machines may reside on a computing device hosting applicationsof other clients, thus the virtual machines may become unavailable orsuffer degraded performance due to activities of other clients ormaintenance of the cloud provider. In addition, the resource needs of amedia content in processing and delivering may change over time, thusthe resource requests may need be adjusted dynamically.

Prior art has disclosed automating video work flows in a video streamingplatform, see for example, U.S. patent application Ser. No. 12/789,024by Mio Babic, entitled “Video Workflow Automation Platform,” and U.S.Pat. No. 8,589,992 by Mio Babic, entitled “Video Workflow AutomationPlatform for Publishing a Video Feed in Multiple Formats.”

SUMMARY

A method implemented in an electronic device serving as a streamdistributor distributing unicast video and audio streams of a streamingplatform system is disclosed. The stream distributor receives a unicastdata flow containing data of a video and audio stream from a loadbalancer of the streaming platform system and distributing to one ormore workers of the streaming platform system to process, the unicastdata flow being transmitted in user datagram protocol (UDP) packets. Themethod includes the electronic device detecting initiation of amaintenance activity on a virtual machine or its host associated withthe stream distributor, where the virtual machine is a part of a cloudcomputing environment of the streaming platform system. The method alsoincludes the electronic device indicating a failure mode of the streamdistributor, where the failure mode indication is to cause the loadbalancer to switch the unicast data flow to an alternate streamdistributor. The method also includes the electronic device detecting acompletion of the load balancer switching the unicast data flow to thealternate stream distributor, and halting the distribution of theunicast data flow to the one or more workers.

An electronic device to serve as a stream distributor distributingunicast video and audio streams of a streaming platform system. Thestream distributor receives a unicast data flow containing data of avideo and audio stream from a load balancer of the streaming platformsystem and distributing to one or more workers of the streaming platformsystem to process, the unicast data flow being transmitted in userdatagram protocol (UDP) packets. The electronic device contains anon-transitory machine-readable storage medium to store the streamdistributor and a processor coupled to the non-transitorymachine-readable storage medium. The processor to execute the streamdistributor and the stream distributor is configured to: detectinitiation of a maintenance activity on a virtual machine or its hostassociated with the stream distributor, where the virtual machine is apart of a cloud computing environment of the streaming platform system;indicate a failure mode of the stream distributor, where the failuremode indication is to cause the load balancer to switch the unicast dataflow to an alternate stream distributor; detect a completion of the loadbalancer switching the unicast data flow to the alternate streamdistributor; and halt the distribution of the unicast data flow to theone or more workers.

A non-transitory machine-readable medium is disclosed for distributingunicast video and audio streams of a streaming platform system. Thenon-transitory machine-readable medium, when executed by a processor,cause the processor to perform operations in an electronic deviceserving as a stream distributor distributing unicast video and audiostreams of a streaming platform system, the stream distributor receivinga unicast data flow containing data of a video and audio stream from aload balancer of the streaming platform system and distributing to oneor more workers of the streaming platform system to process, the unicastdata flow being transmitted in user datagram protocol (UDP) packets. Theoperations include detecting initiation of a maintenance activity on avirtual machine or its host associated with the stream distributor,where the virtual machine is a part of a cloud computing environment ofthe streaming platform system. The operations further include indicatinga failure mode of the stream distributor, where the failure modeindication is to cause the load balancer to switch the unicast data flowto an alternate stream distributor. The operations further includedetecting a completion of the load balancer switching the unicast dataflow to the alternate stream distributor, and halting the distributionof the unicast data flow to the one or more workers.

Embodiments of the invention aim at flexibly processing media contentsuch as real time video and audio streams in a network cloud and thecreated methods and systems allow unicast video and audio streams to bedistributed reliably, similar to multicast video and audio streams, thuspermit the streaming platform to operate efficiently and reliably usinga wide range of cloud infrastructure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings in which likereferences indicate similar elements. It should be noted that differentreferences to “an” or “one” embodiment in this specification are notnecessarily to the same embodiment, and such references mean at leastone. Further, when a particular feature, structure, or characteristic isdescribed in connection with an embodiment, it is submitted that it iswithin the knowledge of one skilled in the art to affect such feature,structure, or characteristic in connection with other embodimentswhether or not explicitly described.

FIG. 1 illustrates a video streaming platform in a cloud computingenvironment according to one embodiment of the invention.

FIG. 2 is a flow diagram illustrating the method of creating adistributed graph of tasks at a video streaming platform in a cloudcomputing environment according to one embodiment of the invention.

FIG. 3A illustrates an exemplary task graph according to one embodimentof the invention.

FIG. 3B illustrates a task graph revision according to one embodiment ofthe invention.

FIG. 3C illustrates a task group split according to one embodiment ofthe invention.

FIG. 4A illustrates headers of packets of the incoming data flowaccording to one embodiment of the invention.

FIG. 4B illustrates the relationship between adjacent nodes in a portionof a task graph according to one embodiment of the invention.

FIG. 5 illustrates coordinating stream processing at a video streamingplatform in a cloud computing environment according to one embodiment ofthe invention.

FIG. 6 is a flow diagram illustrating the operations of a worker incoordination with an orchestrator of a streaming platform according toone embodiment of the invention.

FIG. 7 illustrates the execution of a task running process reading aninput at a worker according to one embodiment of the invention.

FIG. 8 is a flow diagram illustrating the execution of a task runningprocess reading an input at a worker according to one embodiment of theinvention.

FIG. 9 illustrates the execution of a task running process producing anoutput at a worker according to one embodiment of the invention.

FIG. 10 is a flow diagram illustrating the execution of a task runningprocess producing an output at a worker according to one embodiment ofthe invention.

FIG. 11 illustrates a video streaming platform for unicast video in acloud computing environment according to one embodiment of theinvention.

FIG. 12 illustrates interaction of a load balancer and a set of streamdistributors according to one embodiment of the invention.

FIG. 13 is a flow diagram illustrating operations on a streamdistributor of a streaming platform in a cloud computing environmentupon detecting initiation of a maintenance activity according to oneembodiment of the invention.

FIG. 14 is a block diagram illustrating an electronic device that mayserve as an orchestrator of a streaming platform in a cloud computingenvironment according to one embodiment of the invention.

FIG. 15 is a block diagram illustrating an electronic device that mayserve as a worker of a streaming platform in a cloud computingenvironment according to one embodiment of the invention.

FIG. 16 is a block diagram illustrating an electronic device that mayserve as a stream distributor of a streaming platform in a cloudcomputing environment according to one embodiment of the invention.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth.However, it is understood that embodiments of the invention may bepracticed without these specific details. In other instances, well-knowncircuits, structures and techniques have not been shown in detail inorder not to obscure the understanding of this description. It will beappreciated, however, by one skilled in the art that the invention maybe practiced without such specific details. Those of ordinary skill inthe art, with the included descriptions, will be able to implementappropriate functionality without undue experimentation.

References in the specification to “one embodiment,” “an embodiment,”“an example embodiment,” etc., indicate that the embodiment describedmay include a particular feature, structure, or characteristic, butevery embodiment may not necessarily include the particular feature,structure, or characteristic. Moreover, such phrases are not necessarilyreferring to the same embodiment. Further, when a particular feature,structure, or characteristic is described in connection with anembodiment, it is submitted that it is within the knowledge of oneskilled in the art to effect such feature, structure, or characteristicin connection with other embodiments whether or not explicitlydescribed.

Bracketed text and blocks with dashed borders (e.g., large dashes, smalldashes, dot-dash, and dots) may be used herein to illustrate optionaloperations that add additional features to embodiments of the invention.However, such notation should not be taken to mean that these are theonly options or optional operations, and/or that blocks with solidborders are not optional in certain embodiments of the invention.

In the following description and claims, the terms “coupled” and“connected,” along with their derivatives, may be used. It should beunderstood that these terms are not intended as synonyms for each other.“Coupled” is used to indicate that two or more elements, which may ormay not be in direct physical or electrical contact with each other,co-operate or interact with each other. “Connected” is used to indicatethe establishment of communication between two or more elements that arecoupled with each other. A “set,” as used herein refers to any positivewhole number of items including one item.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise as apparent from the following discussion,it is appreciated that throughout the description, discussions utilizingterms such as “receiving,” “monitoring,” “creating,” “estimating,”“splitting,” “updating,” “executing,” “selecting,” “initiating,”“indicating,” “reading,” “writing,” “registering,” “replicating,”“receiving,” “communicating,” “presenting,” “provisioning,”“publishing,” “processing,” “providing,” “computing,” “calculating,”“determining,” “displaying,” or the like, refer to the actions andprocesses of a computing system, or similar electronic computingsystems, that manipulates and transforms data represented as physical(e.g., electronic) quantities within the computing system's registersand memories into other data similarly represented as physicalquantities within the computing system memories or registers or othersuch information storage, transmission or display devices.

An electronic device stores and transmits (internally and/or with otherelectronic devices over a network) code (which is composed of softwareinstructions and which is sometimes referred to as computer program codeor a computer program) and/or data using machine-readable media (alsocalled computer-readable media), such as machine-readable storage media(e.g., magnetic disks, optical disks, read only memory (ROM), flashmemory devices, phase change memory) and machine-readable transmissionmedia (also called a carrier) (e.g., electrical, optical, radio,acoustical or other form of propagated signals—such as carrier waves,infrared signals). Thus, an electronic device (e.g., a computer)includes hardware and software, such as a set of one or more processorscoupled to one or more machine-readable storage media to store code forexecution on the set of processors and/or to store data. For instance,an electronic device may include non-transitory machine-readable memorycontaining the code since the non-transitory machine-readable memory canpersist code/data even when the electronic device is turned off (whenpower is removed), and while the electronic device is turned on thatpart of the code that is to be executed by the processor(s) of thatelectronic device is typically copied from the slower non-transitorymachine-readable memory into transitory machine-readable memory (e.g.,dynamic random access memory (DRAM), static random access memory (SRAM))of that electronic device. Typical electronic devices also include a setor one or more physical network interface(s) to establish networkconnections (to transmit and/or receive code and/or data usingpropagating signals) with other electronic devices. One or more parts ofan embodiment of the invention may be implemented using differentcombinations of software, firmware, and/or hardware.

A Video Streaming Platform in a Cloud Computing Environment

FIG. 1 illustrates a video streaming platform in a cloud computingenvironment according to one embodiment of the invention. Streamingplatform 100 is a computing system, and it contains one or more machinesincluding one or more server computers, gateways, routers, or othercomputing/networking electronic devices. A streaming platform operatormanages operations of streaming platform 100, yet some or all of theelectronic devices within the streaming platform 100 may be owned by athird party (e.g., a cloud provider/operator such as Amazon.com®,Microsoft®, Rackspace®, or Computer Sciences Corporation (CSC®)). Thatis, a cloud computing environment operated by a cloud provider/operatormay host the streaming platform.

Streaming platform 100 receives its data flow input from video source110. Video source 110 contains one or more Internet Packet (IP) packetstreams in one embodiment. The IP packet streams may contain one or morelive video feeds. A live video feed may be video of a live event or liveperformance, or may be video of a prerecorded event being played backaccording to a schedule. The live video feed may be a video broadcastedover cable, satellite, or over-the-air. Note the terms “video,” “videosource,” and “video feed,” as used herein, refer to the video andcorresponding audio of the particular recorded event (e.g., TV show,performance, sporting event, etc), but also may include video only. Thusthe video source (sometimes referred to as the video and audio streams)of streaming platform 100 may contain only video. The video source maybe a webcast of a television broadcast, such as of a sporting event, alive or recorded performance, a live or recorded news report, or thelike. A live event may also have prerecorded content intermingled withlive media content, such as advertisements, which are played in betweenthe live telecast. It should be noted that the embodiments of theinvention described herein may also be used for streamingvideo-on-demand (VOD).

Video source 110 may be “pushed” to streaming platform 100 where thevideo source is IP packet streams such as the moving pictures expertgroup—transport streams (MPEG-TS) or a type of adaptive bitratestreaming streams (streams implemented in protocols such as MPEG-DynamicAdaptive Streaming over HTTP (DASH), Microsoft® Smooth Streaming, orApple® HTTP Live Streaming). The IP packet streams logically flow tostreaming platform 100 from an external source thus video source 110 isreferred to as being pushed to streaming platform 100.

Video source 110 may also be “pulled” by a processing unit (referred toas a worker) of streaming platform 100, where the worker runs one ormore processing tasks. The worker may initiate a Transmission ControlProtocol (TCP) connection to an external uniform resource identifier(URI) (an external uniform resource locator (URL) or an external uniformresource name (URN)), and after performing a protocol handshake, causeinbound IP packet streams to flow directly into the worker for one ormore processing tasks without being processed by the optional streaminput interface 102 or stream coordinator 170. The pull of video feedsmay be implemented through the real time messaging protocol (RTMP),where the processing task includes a RTMP capture task.

Stream input interface 102 is a logical input point for data flows intostreaming platform 100. It may not be present as a physical entity ofstreaming platform 100 in one embodiment. Incoming data flow 180 mayoptionally go to stream coordinator 170 (the operations of streamcoordinator 170 are detailed herein below). The incoming data flowcontains data of one or more video and audio streams. In one embodiment,the incoming data flow is transmitted in user datagram protocol (UDP)packets.

FIG. 4A illustrates headers of packets of the incoming data flowaccording to one embodiment of the invention. The packet contains an IPheader at reference 408, and it has a UDP header on top of IP header atreference 406. As a stateless protocol, UDP is not as reliable as TCP.Thus, the packet may optionally contain a real-time transport protocol(RTP) header at reference 404, where the RTP header adds additioninformation to allow the receiving end of the data flow to reorder thereceived packet and recover from certain level of packet loss. Thepacket further contains one or more MPEG-TS packets at reference 402.During transmission, the size of a typical UDP payload is limited toaround 1,400 bytes in one embodiment in order to minimize fragmentationwithin and across public networks, which at higher video bit rates cancause very high packet arrival rates (e.g., 25 Megabits/sec=2232 UDPpackets/sec).

While TCP is a lossless transport protocol and can be used to transmitthe incoming data flow, TCP based transmission may come at the expenseof significantly variable delay in circumstances where networkcongestion may occur. In the cloud computing environment, due toresource sharing among multiple clients, a data flow may experiencenetwork congestion. In addition, using TCP-based source such as RTMP forvideo delivery significantly complicates the ability to retrieveredundant input signals via multiple data flows, since each TCP dataflow comes with its own unique delay and protocols such as RTMP do nothandle transport-level synchronization well. Thus, at a streamingplatform in the cloud computing environment, UDP is preferable indelivering video source.

The incoming data flow may be multicast or unicast. When the incomingdata flow is a multicast data flow, it sends packets to multipledestinations simultaneously. In streaming platform 100, the multipledestinations include multiple workers, and incoming data flow 180multicasts into distributed data flows 182 and is transmitted to workers152-158. When the incoming data flow is a unicast data flow, streamcoordinator 170 converts the unicast data flow into distributed dataflows 182 thus workers 152-158 process them indiscriminately.

Workers may be organized as worker clusters in a streaming platform. Instreaming platform 100, workers 152-158 are in primary worker cluster150, which contains workers actively working on processing tasks.Workers 162-168 are in backup worker cluster 160, which contains workersremains standby thus provides redundancy and robustness for streamingplatform 100. Workers perform tasks through coordination with one ormore orchestrators, which may form an orchestrator cluster.

Orchestrator cluster 120 contains orchestrators 122-124 and orchestratordatabase 126 that store data for operations of the orchestrators. Theorchestrators may form working and backup pairs within an orchestratorcluster, and the orchestrator cluster may be paired with anotherorchestrator cluster for redundancy and robustness purpose too.Orchestrator cluster 120 receives operator input 130 and it interactswith worker clusters 150-160 through control flow 185. Operator input130 may be in the form of an application programming interface (API)call, and it may contain a request to create a work flow for a videosource in streaming platform 100. The work flow may be referred to as achannel, each of which represents a processing work flow that transformsan individual incoming data stream into its configured output datastream(s). An orchestrator may also host services responsible for workscheduling and overall system health monitoring and management.

Workers are coupled to one or more orchestrators, and they executeprocessing tasks on the distributed data flows. The data flows areprocessed and the workers produce output data flows 184. Output dataflows 184 may optionally goes through stream output interface 109, alogical output point for the data flows going out of streaming platform100. Note both stream input interface 102 and stream output interface109 may be integrated parts of worker functions and they may not beindividual physical units of streaming platform 100.

Output data flows goes to video destination 190, which contains one ormore IP streams in one embodiment. The output data flows may bedelivered to an ingest point of a content delivery network (CDN). A CDNis a system of computers networked together across the Internet thatcooperates transparently to deliver content, and may include, forexample, one or more origin content servers, web servers, cache servers,edge servers, etc. The output data flows may also be delivered to avideo playback device directly. A single output data flow may bedelivered to multiple destinations through multicast.

Note both workers and orchestrators of the streaming platform may be runon cloud-hosted virtual machines (VMs). The VMs are parts of the cloudcomputing environment hosting the streaming platform and they reside oncomputing systems of the cloud computing environment. These computingsystems are referred to as hosts of the workers and orchestrators in thestreaming platform. The hosts are managed by a cloud provider and theymay concurrently host applications other than the streaming platform.Thus, the workers are not dedicated to the streaming platform and theyare allocated to the streaming platform as needed and according tocoordination of the orchestrators.

Overall, streaming platform 100 ingests video sources, transcodes, andtransforms the video sources into desired one or more formats forpublication and then outputs the resulting video data. The streamingplatform is a distributed architecture using cloud resources, and it isa flexible, scalable, and efficient platform for video processing.

Graph Based Video Data Flow Processing

Traditionally video processing is performed through a batch-oriented,non-real time video on demand architecture. In contrast, embodiments ofthe invention utilize a real-time or near real-time streaming approachvia a distributed graph of tasks. The approach achieves several goals:It may minimize end-to-end system latency for the video sourceprocessing; it offers flexibility for deploying the streaming platforminto diverse cloud hardware infrastructures; and it allows flexibilityto achieve system reliability targets in a given cloud hardwareinfrastructure.

The distributed graph of tasks is utilized in creating the processingwork flow (referred to as a channel) that transforms an individualincoming data stream into its configured output data stream(s). Duringchannel creation, the orchestrator is responsible for compiling achannel definition (e.g., using the JavaScript Objection Notation (JSON)format) into a directed graph of tasks with associated configurationdata and for assigning those tasks into logical groups (referred to astask groups) based on estimated resource requirements. The availableworkers may then poll the orchestrator seeking work that they havesufficient resources to handle. Once assigned one or more task groups, aworker launches appropriate task running processes with the specifiedconfiguration. The task running processes are then executed as part ofthe graph based video data flow processing.

FIG. 2 is a flow diagram illustrating the method of creating adistributed graph of tasks at a video streaming platform in a cloudcomputing environment according to one embodiment of the invention.Method 200 may be implemented on an orchestrator of the video streamingplatform, which also contain workers as the processing units of thestreaming platform.

At reference 202, the orchestrator receives a request to process a videosource. The request may be received through an operator input (e.g., anAPI call) as illustrated in FIG. 1. The request containing parametersdescribing the video source. The request (may be referred to as achannel creation request) may contain a variety of parameters describingthe video source. For example, the request may contain at least one ofthe following:

-   -   Mandatory parameters describing the type of the video source        (e.g., MPEG-2, MPEG-4, H.265, and etc.), and location of the        video source (e.g., ingest protocol, IP address, URI, and etc.).    -   Indication of whether and how to enable subtitle processing        and/or enable advertisement insertion processing for the video        source.    -   The desired video and audio transcoding operations (e.g., how        many audio/video layers, the desired output characteristics for        each such as video frame size/rate and bitrate, the relevant        portion of the incoming data flow to use if applicable) for the        video source.    -   The desired contention protection operations for the video        source (e.g., Microsoft© PlayReady, Adobe© Access DRM, AES-128        Encryption for HTTP live streaming, etc.).    -   The desired publishing operations to output (e.g., which output        format(s) (such as HTTP live streaming (HLS), HTTP dynamic        streaming (HDS), RTMP, or smooth streaming) to publish, and the        destination(s) to send each output format.

Then at reference 204, the orchestrator creates a task graph based onthe received request. The task graph is a directed acyclic graph (DAG)of tasks for processing the video source. A DAG is a directed graph withno directed cycles. The directed graph is formed by a collection ofnodes (also referred to as vertices) and directed edges, each edgeconnecting one node to another, such that there is no way to start at anode and follow a sequence of edges that eventually loops back to thenode. Each node of the task graph represents a processing task, and eachedge represents a data flow across two processing tasks andcorresponding input and output of each processing task.

FIG. 3A illustrates an exemplary task graph according to one embodimentof the invention. Task graph 350 contains one input node, input 1 at380. The input 1 represents an input processing task, which is toreceive and prepare the video source for further processing. The outputof input 1 is sent to nodes audio 331, and video layers 1-6 at 332-337respectively. The nodes represent processing tasks associated with therespective audio and video layers of the video source. After the audioand videos are processed through transcoding operations at 332-337, theoutputs are sent to the node of publisher 386, where the processing taskis to publish the processed video source in desired output format(s) tothe desired destination(s). While the majority of the nodes (331-337) oftask graph 350 only have a single input and a single output, the layoutis for simplicity of illustration. A task graph may contain tens or evenhundreds of nodes, and each node may have multiple inputs and multipleoutputs.

FIG. 4B illustrates the relationship between adjacent nodes in a portionof a task graph according to one embodiment of the invention. The taskgraph is task graph 350 illustrated in FIG. 3A, and the illustratedportion includes audio layer 331, video layer 1 at 332, publisher 386,and edges 422-424. Audio layer 331 produces one output. The outputcontains output parameter 451, which is referred to by an outputresource name (output_(—)1_resource_name) and the value isaudio_(—)1_output. Represented by edge 422, the output of audio layer331 is an input of publisher 386, and that input contains inputparameter 452, which is referred to by an input resource name(input_(—)1_resource_name), and the value of the input parameter topublisher 386 is the same as the value of the output parameter 451,audio_(—)1_output. Similarly, video layer 1 at 332 produces an outputcontaining output parameter 453, which is referred to asoutput_(—)1_resource_name, and the value is video_(—)1_output. Theoutput of video layer 1 at 332 is another input of publisher 386, andthat input contains input parameter 454, which is referred to byinput_(—)2_resource_name and its value is the same (video_(—)1_output).

Note that while the input and output parameters in the example aresingle values respectively, some edges of a task graph may contain aplurality of input parameters and/or a plurality of output parameters,in which case the input parameters and output parameters are referred toas the input parameter set and the output parameter set respectively.Each of the input and output resource names represents resource(s)involved for the respective inputs and outputs. The reading and writingof the inputs and outputs are done via API calls to a service called thesegment store that runs on every worker in one embodiment. Furtherdetails of the operations of the segment store are disclosed hereinbelow.

Referring back to FIG. 2, after the task graph is created, theorchestrator estimates resource requirements for each processing taskrepresented in the task graph at reference 206. The estimation ofresource requirements may be based on a variety of factors, includingone or more of the following:

-   -   Storage usage of each processing task during its execution        cycle. A processing task may store data for diagnostics and        monitoring prior, during, and after its execution, and the total        storage need and the changing storage need over time are        resource requirements to be considered.    -   Communication bandwidth usage of each processing task during its        execution cycle. A processing task may need certain (changing)        bandwidth for communication during its execution cycle.    -   Computing resource consumption of each processing task during        its execution cycle. The computing resource consumption may be        an absolute or relative usage of a central processing unit        (CPU), a graphics processing unit (GPU), or other processing        units of the processing tasks. The estimation can be complicated        when the orchestrator considers various characteristics of one        or more inputs of a processing task. For example, the estimated        CPU/GPU usage may vary widely with inputs having different frame        sizes, frame rates, input encoding/decoding (codec) schemes, and        presumed content complexity (e.g., talking head vs. high motion        sports). In one embodiment, orchestrator may over-estimate        computing resource consumption of each processing task to avoid        complicated computation in making the estimation and to avoid        fragmentation of available computing resources into unusably        small units.

Note the estimation of resource requirements may utilize one or moremachine-learning algorithms to allow the orchestrator make betterestimation over time. In which case, an earlier estimation of resourcerequirements is used for workers to execute processing tasks, and theworker may provide feedback about the accuracy of the estimation. Usingthe feedback, the orchestrator may adjust its estimation of resourcerequirements for a same or similar processing task or video source inthe future. The feedback loop may constantly improve the accuracy of theestimation of resource requirements. Thus, the estimation may bereferred to as a prediction, which is made based on the characteristicsof a video source and the similarity of the characteristics of the videosource comparing to an earlier video source processed by the streamingplatform.

The flow optionally goes to reference 208, where the orchestratorrevises the task graph. The revision may be based on the estimation ofthe total resource requirements of the processing tasks for a channel.For example, the computational resource requirements for the processingtasks may be too much for a single VM that hosts a worker being assignedthe processing tasks for the channel, thus the graph may be revised tosplit the processing tasks into two groups. FIG. 3B illustrates a taskgraph revision according to one embodiment of the invention. The taskgraph in FIG. 3B is similar to the one in FIG. 3A, but it has two inputsinstead of one: Input 1 at 382 and input 2 at 384. The processing taskof input 1 at 380 in FIG. 3A is split into two in FIG. 3B. The split maybe due to redundancy requirements of input 1 at 380 or may be done inorder to minimize the networking utilization across multiple workers(often implemented on multiple VMs in one embodiment). For example, theorchestrator may determine that a video processing task is toocomputationally intensive to be processed by a single worker. In theexample in FIGS. 3A-B, input 1 at 380 corresponds to an input of a workflow where a single worker does not have sufficient resources to processthe entire graph. Since input redundancy is important in this example,input 1 at 380 is cloned into two inputs, input 1-1 and input 2-2 at 382and 384 respectively, where the two inputs are collocated to produceoutputs to respective sets of processing tasks. Of course, the split ofprocessing tasks for the audio, the video layers, and the publisher mayalso be performed in task graph revision as needed.

In an alternative embodiment, a video processing task is split into twocooperating tasks that together achieve the same processing results asthe original task, but are assigned to two separate task groups forexecution on two workers. In one embodiment, a streaming videoprocessing task can be split in two based on time partitioning of thetask, with one task handling half of the input data alternating with theother task handling the remaining input data. The cloning of processingtasks and time partition of processing tasks are only two exemplary waysto revise task graphs, and others may be implemented utilizing theprinciple of embodiments of the invention.

The revision may also be based on a redundancy requirements of one ormore processing tasks. For some video source, the streaming platform isrequired to provide redundancy in processing (e.g., the requirement isdictated through a service level agreement (SLA) between a client andthe operator of the streaming platform). In that case, orchestrator maytie certain tasks associated with the video source to either a workingor backup worker cluster and that will cause revision of the task graph.

Referring back to FIG. 2, the orchestrator then splits the task graphinto multiple subsets at reference 210. Each subset of the task graphcorresponds to a task group to be executed by one or more workers of thestreaming platform. A task group contains a set of processing tasks thatthe orchestrator allocates to be executed by one or more workers. In oneembodiment, each subset of the task graph corresponds to a task group tobe executed by a single worker.

FIG. 3C illustrates a task group split according to one embodiment ofthe invention. In the task group split 354, the revised task group 350is split into two task groups: Task group 372 including processing tasksinput 1, audio, video layer 1-3, and publisher, and task group 374,including processing tasks input 2, and video layer 4-7. Each of taskgroups 372 and 374 are to be executed by a single worker of thestreaming platform. Each worker may run on a single VM of the cloudcomputing environment on which the streaming platform is operating.

Note that after either the task graph revision at reference 208 or thetask graph split at reference 210, the orchestrator may go back toreference 206 to re-estimate the resource requirements of processingtasks as the task graph revision and split may impact workloads (e.g.,storage usage, communication bandwidth usage, and computing resourceconsumption) associated with processing tasks. In an alternateembodiment, the orchestrator simply overestimates the resourcerequirements of the processing tasks to allow for changes of workloads.

Then optionally at reference 212, the orchestrator stores a status ofeach subset of the task graph and updates the status of each subset whenthe subset is allocated to one or more workers for execution. In oneembodiment, the orchestrator stores the status in orchestrator database126 as illustrated in FIG. 1. Thus the orchestrator keeps up-to-dateinformation of task allocation for each video source. Note method 200 isdescribed using one video source, in practice, an orchestrator mayallocate workers for many video sources concurrently.

Also note that the creation, revision, and split of the task graph isbased on the request to process the video source only, and theoperations do not need the video source being available to the streamingplatform. Orchestrator may perform the operations without knowing theavailability and health of the workers of the streaming platform.

Coordinating Stream Processing at a Video Streaming Platform

As discussed herein above, a task graph is split into multiple subsetsand each subset corresponds to a task group to be executed by one ormore workers. The execution of the task group is performed at the one ormore workers with coordination of the orchestrator. FIG. 5 illustratescoordinating stream processing at a video streaming platform in a cloudcomputing environment according to one embodiment of the invention. Thestreaming platform 100 is the same as the one in FIG. 1, but entitiesnot essential to the discussion of the coordination are omitted in FIG.5 for clarity of discussion. Task boxes 1 to 4 illustrate the order inwhich operations are performed according to one embodiment of theinvention.

Worker 152 is a worker with available resources to execute one or moreprocessing tasks. In one embodiment, worker 152 is idle withoutexecuting any processing task. At task box 1, worker 152 requests a taskgroup from the orchestrator. The request may take the form of a periodicAPI call to the orchestrator in one embodiment.

At task box 2, the worker receives a task group allocated for the workerfrom the orchestrator. The received data may be a message including anidentifier of the task group allocated to the worker. The orchestratormay update the status of the task group upon allocating the task groupto the worker. The allocation is based at least partially oncharacteristics of the worker. For example, the characteristics mayinclude:

-   -   The role of the cluster of the worker (primary cluster vs.        backup cluster).    -   Current and/or historical health statuses of the worker (working        function normally or having degraded performance)    -   The software versions of and the functionalities supported by        the worker.    -   The hardware capability of the host computing devices of the        worker.

Then at task box 3, the worker initiates one or more task runningprocesses to execute the allocated task group. Each task running processcorresponds to one processing task in the task group, where eachprocessing task corresponds to a node of the task graph created by theorchestrator. The operations to execute the allocated task group arediscussed in more details herein below. In an alternate embodiment, theworker isolates tasks from each other during execution using lighterweight mechanisms (e.g. application domains, containers, etc.) insteadof OS processes.

Optionally at task box 4, the orchestrator monitors the execution oftask running processes and causes them to abort and/or restart uponfailure/recovery. The worker obtains a status of each of the taskrunning processes during their execution cycles from the task runningprocesses. The health indication of a task running processes may beupdated dynamically during its execution cycle. An updated status may besent to the orchestrator upon a certain event (e.g., failure/performancedegradation of the worker) via an API call in one embodiment. Inalternative, the orchestrator may probe the worker periodically todetermine the current status of the task running processes. Upondetermining the failure/performance degradation of the worker, theorchestrator may cause the task running process to abort and go througha diagnostic procedure to restart the task running process uponrecovery. In an alternate embodiment, the worker may cause the taskrunning process to abort and go through the diagnostic procedure torestart the test running process.

FIG. 6 is a flow diagram illustrating the operations of a worker incoordination with an orchestrator of a streaming platform according toone embodiment of the invention. Method 600 may be implemented in aworker such as worker 152 as illustrated in FIG. 5.

At reference 602, the worker requests a task group from the orchestratorof the streaming platform. Then at reference 606, the worker receivesthe task group allocated for the worker from the orchestrator. Theallocation is based at least partially on characteristics of the worker.The task group corresponds to a subset of a task graph of theorchestrator. The task graph is a directed acyclic graph of tasks asdiscussed herein above in relating to FIGS. 2-4.

Referring back to FIG. 6, at reference 608, the worker initiates one ormore task running processes to execute the allocated task group, whereeach task running process executes a processing task corresponding to anode of the task group. The execution includes at least one of (1)processing one or more inputs corresponding to an incoming edge to thenode; and (2) producing one or more outputs corresponding to one or moreoutgoing edges from the node. Thus, the processing task may process oneor more inputs without producing any output, produce one or more outputswithout processing any input, or perform both the processing theinput(s) and producing the output(s).

At reference 610, the one or more task running processes indicate theirrespective statuses during the execution cycles. Each status may beutilized to determine aborting or restarting a task running process. Inone embodiment, the status is utilized by the worker to make thedetermination. In an alternate embodiment, the status is utilized by theorchestrator to make the determination. The status may be updateddynamically after one or more conditions are met, such as an eventhappens (e.g., the process failed or its performance is degraded) or atimer expires.

Embodiment of Executing a Task Running Process

Executing a task running process at a worker is one key feature of thegraph based video streaming platform in a cloud computing environment.FIG. 7 illustrates the execution of a task running process reading aninput at a worker according to one embodiment of the invention. Thestreaming platform 100 is the same as the one in FIG. 1, but entitiesnot essential to the discussion of the coordination are omitted in FIG.7 for clarity of discussion. Task boxes 1 to 4 illustrate the order inwhich operations are performed according to one embodiment of theinvention.

For executing a task running process at a worker, the task runningprocess interacts with a service called the segment store that runs oneach worker in one embodiment. The task running process reads input andwrites output via API calls to the segment store. The segment store isresponsible for advertising locally created logical resource names witha central resource registry, for storing a sliding window of recent datain memory for each resource, for resolving any requests to read logicalresources via the central resource registry, and for establishing mirrorcopies of logical resources in the local segment store via a cross-VMstreaming network protocol. Note that the central resource registry isprovided by a resource registry service, and the resource registryservice may be provided by the orchestrator or a domain name system(DNS).

By abstracting away the network protocol and name resolution of logicalresource names behind the API calls to the segment store, all processingtasks may be executed in a location agnostic fashion, which achievesmaximum flexibility by centralizing resource placement decisions withinthe orchestrator's graph compilation and resource scheduling services.The processing tasks simply write data as necessary to the outputs andread data as necessary from the inputs.

Note that a worker may execute multiple task running processes, and theymay be coordinated by a task manager (not shown), a service of theworker. The task manager spawns one task running process for each task,passing one or more parameters (referred to as a parameter set)associated with the task. Thus, the task manager may manage many taskrunning processes on a worker simultaneously.

The operations of a task running process are illustrated through thetask boxes 1-4. At task box 1, the task running process 750 requests toread a named resource of the task corresponding to the tasking runningprocess. In this example, the named resource is resource Z. Z is thelogical name of an input which was supplied in the processing task'sinput parameter set, which was created during graph creation andmaintained during any revision and split as discussed above in relatingto FIGS. 2-4. Task running process 750 then looks for the named resourceZ at segment store 752 of the worker (referred to as the local segmentstore).

If task running process 750 finds resource Z at the local segment store,it reads resource Z from the local segment store as the input arrivesfrom another processing task or the incoming data flow for executing thetask. However, task running process 750 may not find resource Z at thelocal segment store, in which case segment store 752 obtains resourceresolution of resource Z from a resource registry service at task box 2.The resource registry service may be provided by a central resourceregistry stored in orchestrator database 126 in one embodiment. Inanother embodiment, the central resource registry is stored by a DNS asdiscussed herein above.

In this example, the central resource registry is stored in orchestratordatabase 126, and the resolution points to segment store 772 as thelocation of resource Z at reference 774. Segment store 772 is a servicein another worker, worker 154. In one embodiment, the location ofresource Z is provided in a message containing the location informationusing the format of IP: port from the central resource registry tosegment store 752.

Then at task box 3, segment store 752 replicates data of the resolvedresource Z into the local segment store 752 through a replicationconnection to the source location at reference 774. In one embodiment,segment store 752 initiates a TCP connection to the source location atreference 774 on the designated IP: port location of segment store 772,and initiates a streaming resource replication connection of resource Z.At task box 4, the task running process 750 reads from the local copy ofresource Z in performing the task running process to execute the task.

FIG. 8 is a flow diagram illustrating the execution of a task runningprocess reading an input at a worker according to one embodiment of theinvention. Method 800 is an embodiment of operations in reference 608 ofFIG. 6 according to one embodiment of the invention. Method 800 may beperformed for each incoming edge of a node of a task graph, where thenode corresponds to the processing task performed by a worker. Method800 is performed by the worker, or more specifically by a task runningprocess and a segment store of the worker.

At reference 802, in order to execute a processing task corresponding tothe node, for each incoming edge, the task running process reads aninput parameter set corresponding to the incoming edge to the node fromthe segment store, which stores resources of the worker. The inputparameter set maps to a resource required to execute the processingtask. At reference 806, the segment store determines whether theresource is within the segment store of the worker (referred to as thelocal segment store) or not. If the resource is within the segment storeof the worker, the flow goes to reference 812, where the segment storeprovides the data for the task running process to utilize in executingthe processing task.

If the resource is not within the segment store of the worker, the flowgoes to reference 808, where the segment store obtains resourceresolution of the resource from a registry service, which provides aresource location of the resource. The registry service may be providedby a central resource registry at the orchestrator or a DNS at adifferent location of the cloud computing environment.

At reference 810, the segment store of the worker replicates data of theresolved resource into the segment store of the worker through areplication connection to the source location. As discussed hereinabove, the replication connection may include a streaming resourcereplication connection of the resolved resource, which may be stored ina segment store of another worker. After the data is replicated in thelocal segment store, the flow goes to reference 812 again, and thesegment store provides the (replicated) data for the task runningprocess to utilize in executing the processing task.

In contrast to FIG. 7, FIG. 9 illustrates the execution of a taskrunning process producing an output at a worker according to oneembodiment of the invention. The streaming platform 100 is the same asthe one in FIG. 1, but entities not essential to the discussion of thecoordination are omitted in FIG. 9 for clarity of discussion. Task boxes1 to 4 illustrate the order in which operations are performed accordingto one embodiment of the invention.

At task box 1, task running process 750 requests to create a namedresource for output at segment store 752 of worker 152. The task runningprocess produces output as it executes a processing task, and the namedresource is where the produced output will be referred. The namedresource (referred to as resource Q in this example) maps to an outputparameter set corresponding to the outgoing edge from the node of thetask graph.

At task box 2, segment store 752 registers resource Q to a resourceregistry service. In this example, the resource registry service isprovided by orchestrator database 126, which contain a central resourceregistry. In an alternative embodiment though, the resource registryservice may be provided by a DNS or another entity within the cloudcomputing environment. In one embodiment, the central resource registrystores with a resource registration API the name of the resource(resource Q) and its current location (e.g., using the format of IP:port) indicating that resource Q is in segment store 752.

Then at task box 3, the task running process creates the named resourceand writes data to resource Q 756, which is at the local segment store(segment store 752) of worker 152. At task box 4, if a replicationconnection is established for resource Q in segment store 752, the databeing written to resource Q are copied to all segment stores having thereplication connection to resource Q. Note while creating the namedresource is illustrated after registering the resource in the figure,the operations may occur simultaneously or the creating the namedresource occurs prior to the registering the resource in an alternativeembodiment.

FIG. 10 is a flow diagram illustrating the execution of a task runningprocess producing an output at a worker according to one embodiment ofthe invention. Method 1000 is an embodiment of operations in reference608 of FIG. 6 according to one embodiment of the invention. Method 1000may be performed for each outgoing edge of a node of a task graph, wherethe node corresponds to the processing task performed by a worker.Method 1000 is performed by the worker, or more specifically by a taskrunning process and a segment store of the worker.

At reference 1002, in order to execute a processing task correspondingto the node, for each outgoing edge, the task running process requeststo create a resource, where the resource maps to an output parameter setcorresponding to the outgoing edge from the node. At reference 1006, thesegment store registers the resource in a resource registry service,which may reside in the orchestrator, a DNS or other entities of thecloud computing environment.

At reference 1008, the resource is created in the segment store of theworker. Then the processing task writes data to the resource inexecuting the processing task at reference 1010. Optionally at reference1012, the segment store replicates data of the resource to all segmentstores having replication connections to the resource. Thewriting/replicating of data is an iterative process, thus the processdoes not complete until all data to be written/replicated are finished.

Ensuring Reliability of Unicast Video Streaming

As discussed herein above, at a streaming platform in the cloudcomputing environment, UDP is preferable in delivering video sourcedata. Multicasting UDP data flows has the advantage of simultaneouslysending packets to multiple workers thus multiple workers may executeprocessing tasks, avoiding single point of failure. Yet, many publiccloud computing environments do not support IP multicast for technology,security, and business reasons. In addition, the same public cloudcomputing environment does not guarantee the availability of anyparticular VM that may be utilized by a worker of the streamingplatform.

For a particular VM, both planned and unplanned maintenance activitiesmay occur, and the hardware hosting the particular VM may fail too, allof the failure and maintenance activities reduces reliability of unicastvideo streaming that counts on reliability of the particular involvedVMs in those public cloud computing environment. Thus, in a streamingplatform, it is preferable for every worker receive an identicallow-latency copy of every input packet to maximize video sourceavailability. Without available IP multicast in the cloud computingenvironment, the streaming platform may build a component designedspecifically to handle the high packet rate of unicast UDP streams andselectively forward copies of those packets at the line rate or near theline rate to the correct workers.

FIG. 11 illustrates a video streaming platform for unicast video in acloud computing environment according to one embodiment of theinvention. Streaming platform 1100 is similar to streaming platform 100of FIG. 1. The same or similar references indicate elements orcomponents having the same or similar functionalities and elements orcomponents not essential to the embodiment of the invention is omittedin FIG. 11.

The component built specifically to handle the high packet rate ofunicast UDP streams is a set of stream distributors 132-134, which alongwith load balancer 146, is a part of stream coordinator 170 in oneembodiment. Load balancer 146 is a common component of a cloud computingenvironment, and it is used to distribute workloads across multiplecomputing resources. Load balancing may aim at optimizing processing ofincoming unicast data flow 101 using a variety of criteria, such asoptimizing resource use, maximizing throughput, minimizing responsetime, and/or avoiding overload of resources.

In one embodiment, each packet of incoming unicast data flow 101 is sentto one of the set of stream distributors 132-134. The selection of astream distributor is at least partially based on a hash value computedfrom the source IP: port and destination IP: port of the packet in oneembodiment. Since one unicast data flow generally generates the samehash value, all packets of an incoming unicast flow goes through thesame stream distributor. At the selected stream distributor, each packetis broadcasted to all workers 152-158 of primary worker cluster 150.Since the unicast UDP packets of incoming unicast data flow 101 arebroadcasted to all the workers, sometimes a stream distributor isreferred to as a UDP fanout. In another embodiment, the packet isbroadcasted to the subset of workers 152-158 which are runningprocessing tasks for video source associated with the packets.

The set of stream distributors 132-134 may be software modulesimplemented in a VM of the hosting cloud computing environment ofstreaming platform 1100. The VM is implemented on a computing systemsuch as a computer server (often referred to a host of the VM) in thecloud computing environment. The set of stream distributors 132-134 maybe integrated to the electronic device serving as orchestrator cluster120. The dotted box indicates orchestrator integrated with the streamdistributors at reference 130.

With the stream distributors broadcasting UDP packets to a set ofworkers processing the video source, the input data to the task graphfor each video source is consistently available on all workers executingprocessing tasks for that video source. That allows for both (1) apartial layer failure where one of a number of workers executingprocessing tasks according to the task graph dies, and (2) rapidrestart/connection on a new worker executing processing tasks duringstartup and reconnect/failure handling. A stream distributor may alsoadd functionalities to provide dual network paths for the input unicastdata flows, to handle time-shifted input unicast data flows, and toprovide error correction and packet reconstruction to the unicast dataflows.

Given the expectation that in a cloud computing environment that workersand VMs hosting the workers may be taken offline abruptly formaintenance frequently and the significant impact on the streamprocessing when source data is unavailable, streaming platform 1100should be designed for this kind of case happening and still maintainingaggressive availability target of the streaming platform (e.g., 99.99%per month SLA). Given the importance of the stream distributors, it isvital to ensure availability of the stream distributors upon maintenanceand failure associated with the hosting cloud computing environment ofthe streaming platform.

FIG. 12 illustrates interaction of a load balancer and a set of streamdistributors according to one embodiment of the invention. The streamingplatform 1100 is the same as the one of FIG. 11. The same or similarreferences indicate elements or components having the same or similarfunctionalities and elements or components not essential to theembodiment of the invention is omitted in FIG. 12. Task boxes 1 to 7illustrate the order in which operations are performed according to oneembodiment of the invention.

At task box 1, stream distributor 132 detects initiation of amaintenance activity on a VM or its host associated with the streamdistributor. The maintenance activity may be as planned such as a VMentering a maintenance mode, or unplanned such as VM restarts due toupdate of the cloud computing environment, or hardware failure/degradeof the VM host computer server. The detection of the stream distributormay be based on receiving a notification (e.g., through a callback API)from the VM or its host.

Optionally at task box 2, stream distributor 132 delays the maintenanceactivity for a period of time after detecting the initiation. The delaymay be through interactions between stream distributor 132 and the cloudcomputing environment. For example, stream distributor 132 may postponeacknowledgement to the notification from the VM or its host. The periodof time is a short period that is sufficient to allow load balancer 146to switch one or more unicast data flows being sent to streamdistributor 132 over to an alternate stream distributor (e.g., 5˜15seconds). The short period may be predetermined by the operator ofstreaming platform 1100 in one embodiment. In an alternative embodiment,the short period ends when stream distributor 132 no longer receives UDPpackets of the one or more unicast data flows.

At task box 3, stream distributor 132 indicates a failure mode visibleto load balancer 146. In one embodiment, stream distributor 132 sends afailure mode notification to load balancer 146. In an alternativeembodiment, load balancer 146 sends out periodic probes to the streamdistributors and finds that stream distributor 132 is in a failure mode.The periodic probe may be a hypertext transfer protocol (HTTP) healthcheck call to the stream distributor. The stream distributor in thefailure mode responds with a failure code instead of a success code(e.g. HTTP status code 200).

At task box 4, load balancer 146 switches the one or more unicast dataflows being sent to stream distributor 132 over to an alternate streamdistributor such as stream distributor 134. A stream distributor oftenbroadcasts many data flows simultaneously and once the streamdistributor enters a failure mode, the data flows need to be supportedby other stream distributors. The reallocation of the data flows to theother stream distributors may use techniques known in the art. The dataflows are not necessarily or even likely reallocated to a single streamdistributor, but rather to multiple stream distributors. Thus, streamdistributor 134 is only an example of one of multiple alternate streamdistributors to stream distributor 132 when stream distributor 132broadcasts more than one unicast data flows.

At task box 5, stream distributor 132 detects completion of the switchof the one or more unicast data flows by load balancer 146. Thedetection may be based on that stream distributor 132 no longer receivesUDP packets of the one or more unicast data flows from load balancer 146in one embodiment. In an alternative embodiment, stream distributor 132may utilize a switch completion indication of load balancer 146 to makethe detection.

At task box 6, stream distributor 132 halts distribution of the one ormore unicast data flows to the workers. As the one or more unicast dataflows have now switched to alternate stream distributor(s), which startsforwarding UDP packets of the flows to the workers, stream distributor132 stops forwarding UDP packets of the flows.

At task box 7, stream distributor 132 optionally causes performance ofthe maintenance activity on the VM or the host associated with thestream distributor. The delay at task box 2 temporarily prevents themaintenance activity of the VM/host associated with stream distributor132 from happening, and now that the unicast data flows is switched offfrom stream distributor 132, the maintenance activity may proceed. Inone embodiment, stream distributor 132 sends an acknowledgement to thenotification of initiation of the maintenance activity to cause theperformance.

Through the illustrated operations, the maintenance activity will have aminimal impact to the unicast data originally flowing through streamdistributor 132 to workers 152-158 as the unicast data flows will flowthrough alternate stream distributors such as stream distributor 134.

FIG. 13 is a flow diagram illustrating operations on a streamdistributor of a streaming platform in a cloud computing environmentupon detecting initiation of a maintenance activity according to oneembodiment of the invention. Method 1300 may be performed on a streamdistributor such as stream distributor 132 of FIG. 12.

At reference 1302, the stream distributor detects initiation of amaintenance activity (e.g., halting operations or reboot) on a VM or itshost associated with the stream distributor, the VM is a part of a cloudcomputing environment of the streaming platform system. The host is acomputing device of the cloud computing environment hosting the VM. Thedetection is based on receiving a notification of the maintenanceactivity in one embodiment.

Optionally, the stream distributor delays the maintenance activity for aperiod of time after detecting the initiation at reference 1306. Theperiod of time is to allow the load balancer to switch each of the oneor more unicast data flows currently going through the streamdistributor to an alternate stream distributor. The period of time ispredetermined in one embodiment. In an alternative embodiment, theperiod of time ends upon the stream distributor no longer receiving UDPpackets of the one or more unicast data flows from the load balancer. Inone embodiment, delaying the maintenance activity includes postponingacknowledgement of a notification of the initiation of the maintenanceactivity through interactions with API of the cloud computingenvironment hosting the streaming platform.

At reference 1308, the stream distributor indicates a failure mode,where the failure mode indication is to cause the load balancer toswitch each of the one or more unicast data flows currently goingthrough the stream distributor to an alternate stream distributor. Inone embodiment, the load balancer probes the stream distributor at apredetermined interval to determine whether or not the streamdistributor is in the failure mode. Once the load balancer determinesthat the stream distributor is in the failure mode, the load balancerswitches each of the one or more unicast data flows currently goingthrough the stream distributor to an alternate stream distributor.

At reference 1310, the stream distributor detects completion of switchof each of the one or more unicast data flows to an alternate streamdistributor. In one embodiment, the stream distributor detects thecompletion based on that the stream distributor no longer receives theUDP packets of the one or more unicast data flows from the loadbalancer. In an alternative embodiment, stream distributor 132 utilizesa switch completion indication of the load balancer to make thedetection. At reference 1312, the stream distributor halts distributionof each of the one or more unicast data flows to the workers it used tobroadcast to.

At reference 1314, the stream distributor optionally causes performanceof the maintenance activity of the VM or its hosts associated with thestream distributor. In one embodiment, stream distributor sends anacknowledgement to the notification of initiation of the maintenanceactivity to cause the performance. The cloud computing environment thenperforms the maintenance activity.

After the maintenance activity is complete, the stream distributoroptionally indicates that it is healthy again so that the load balancerswitches each of the one or more switched away unicast data flows backto the stream distributor at reference 1322. The timing of the switchback is implementation dependent. Since workers receive the UDP packetsof the incoming data flows during the switch over and the switch back,the timing does not have significant impact on the workers or theirprocessing tasks.

In the embodiments of the invention described so far, all the UDPpackets and their entire payloads of the unicast data flows areforwarded to all the workers of the primary worker cluster (or to thesubset of workers performing processing tasks for each video source).Yet, for some video source processing, only a subset of the data flowsis needed, and one such a data flow is often called a multiple programtransport stream (MPTS). For example, a streaming platform may extractonly 10˜20 Megabits/sec of data out of a work flow for a MPTS videosource of 50˜100 Megabits/sec for use when processing the work flow.

If the number of workers in the primary worker cluster is fairly largeand the MPTS video source requires a high bandwidth, processing all theUDP packets at the stream distributor may waste network bandwidth at thestream distributor and risk introducing UDP packet loss in transmittingto the stream coordinator, processing in the stream coordinator, andreceiving at the workers. Thus the stream coordinator may performlogical filtering of the desired UDP packets out of the overall dataflow, and only forwarding a portion of the data flow of the incomingvideo source for processing by the workers. The selection of the portionof the data flow is based at least partially on processing tasksexecuted by the workers.

Electronic Devices Implementing Embodiments of the Invention

FIG. 14 is a block diagram illustrating an electronic device that mayserve as an orchestrator of a streaming platform in a cloud computingenvironment according to one embodiment of the invention. The electronicdevice may be a computing device (e.g., a computer server) of a cloudcomputing environment). System 1400 may represent any of theorchestrator described above performing any of the processes or methodsdescribed above. System 1400 can include many different components.These components can be implemented as integrated circuits (ICs),portions thereof, discrete electronic devices, or other modules adaptedto a circuit board such as a motherboard or add-in card of a computingsystem, or as components otherwise incorporated within a chassis of thecomputing system. Note also that system 1400 is intended to show a highlevel view of many components of the computing system. However, it is tobe understood that additional components may be present in certainimplementations and furthermore, different arrangement of the componentsshown may occur in other implementations.

In one embodiment, system 1400 includes processor 1401, memory 1403, andoptionally device units 1404-1408 that are interconnected via a bus oran interconnect 1410. Processor 1401 may represent a single processor ormultiple processors with a single processor core or multiple processorcores included therein. Processor 1401 may represent one or moregeneral-purpose processors such as a microprocessor, a centralprocessing unit (CPU), or processing device. More particularly,processor 1401 may be a complex instruction set computing (CISC)microprocessor, reduced instruction set computing (RISC) microprocessor,very long instruction word (VLIW) microprocessor, or processorimplementing other instruction sets, or processors implementing acombination of instruction sets. Processor 1401 may also be one or morespecial-purpose processors such as an application specific integratedcircuit (ASIC), a cellular or baseband processor, a field programmablegate array (FPGA), a digital signal processor (DSP), a networkprocessor, a graphics processor, a network processor, a communicationsprocessor, a cryptographic processor, a co-processor, an embeddedprocessor, or any other type of logic capable of processinginstructions.

Processor 1401 may communicate with memory 1403, which in an embodimentcan be implemented via multiple memory devices to provide for a givenamount of system memory. Memory 1403 may include one or more volatilestorage (or memory) devices such as random access memory (RAM), dynamicRAM (DRAM), synchronous DRAM (SDRAM), static RAM (SRAM), or other typesof storage devices. Memory 1403 may store information includingsequences of instructions that are executed by processor 1401, or anyother device units. For example, executable code and/or data of avariety of operating systems, device drivers, firmware (e.g., inputoutput basic system or BIOS), and/or applications can be loaded inmemory 1403 and executed by processor 1401. An operating system can beany kind of operating systems, such as, for example, Windows® operatingsystem from Microsoft®, Mac OS®/iOS® from Apple, Android® from Google®,Linux®, Unix®, or other real-time or embedded operating systems such asVxWorks.

Memory 1403 contains operator module 1422, which may perform operationsof an orchestrator in a discussed herein above in relating to method200.

System 1400 may optionally further include I/O devices such as deviceunits 1404-1408, including display control and/or display device unit1404, wireless transceiver(s) 1405, video I/O device unit(s) 1406, audioI/O device unit(s) 1407, and other I/O device units 1408 as illustrated.Wireless transceiver 1405 may be a WiFi transceiver, an infraredtransceiver, a Bluetooth transceiver, a WiMax transceiver, a wirelesscellular telephony transceiver, a satellite transceiver (e.g., a globalpositioning system (GPS) transceiver), or other radio frequency (RF)transceivers, or a combination thereof. System 1400 may also include anultrasound device unit (not shown) for transmitting a conference sessioncode.

Video I/O device unit 1406 may include an imaging processing subsystem(e.g., a camera), which may include an optical sensor, such as a chargedcoupled device (CCD) or a complementary metal-oxide semiconductor (CMOS)optical sensor, utilized to facilitate camera functions, such asrecording photographs and video clips and conferencing. Audio I/O deviceunit 1407 may include a speaker and/or a microphone to facilitatevoice-enabled functions, such as voice recognition, voice replication,digital recording, and/or telephony functions. Other optional devices1408 may include a storage device (e.g., a hard drive, a flash memorydevice), universal serial bus (USB) port(s), parallel port(s), serialport(s), a printer, a network interface, a bus bridge (e.g., a PCI-PCIbridge), sensor(s) (e.g., a motion sensor such as an accelerometer,gyroscope, a magnetometer, a light sensor, compass, a proximity sensor,etc.), or a combination thereof. Optional device units 1408 may furtherinclude certain sensors coupled to interconnect 1410 via a sensor hub(not shown), while other devices such as a keyboard or thermal sensormay be controlled by an embedded controller (not shown), dependent uponthe specific configuration or design of system 1400.

System 1400 may be coupled to a streaming platform such as streamingplatforms 100 and 1100, and the streaming platform may be coupled to astream coordinator, one or more worker cluster (working and/or backup),all discussed herein (e.g., in discussion relating to FIGS. 1, 7, and9). System 1400 may perform methods discussed herein above relating toFIGS. 2-4 and 5-10.

Note that while system 1400 is illustrated with various components, itis not intended to represent any particular architecture or manner ofinterconnecting the components; as such details are not germane toembodiments of the present invention. It will also be appreciated thatan electronic device having fewer components or perhaps more componentsmay also be used with embodiments of the invention.

FIG. 15 is a block diagram illustrating an electronic device that mayserve as a worker of a streaming platform in a cloud computingenvironment according to one embodiment of the invention. FIG. 15 issimilar to FIG. 14, and the same or similar references indicate elementsor components having the same or similar functionalities. One differenceis that Memory 1503 contains worker module 1522, which may performoperations of a worker discussed herein above in relating to method 600,which may include methods 800 and 1000.

FIG. 16 is a block diagram illustrating an electronic device that mayserve as a stream distributor of a streaming platform in a cloudcomputing environment according to one embodiment of the invention. FIG.16 is similar to FIG. 14, and the same or similar references indicateelements or components having the same or similar functionalities. Onedifference is that Memory 1603 contains stream distributor module 1622,which may perform operations of a worker discussed herein above inrelating to method 1300.

Some portions of the preceding detailed descriptions have been presentedin terms of algorithms and symbolic representations of operations ondata bits within a computer memory. These algorithmic descriptions andrepresentations are the ways used by those skilled in conferencingtechnology to most effectively convey the substance of their work toothers skilled in the art. An algorithm is here, and generally,conceived to be a self-consistent sequence of operations leading to adesired result. The operations are those requiring physicalmanipulations of physical quantities.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise as apparent from the above discussion, itis appreciated that throughout the description, discussions utilizingterms such as those set forth in the claims below, refer to the actionand processes of a conference device, or similar electronic computingdevice, that manipulates and transforms data represented as physical(electronic) quantities within the conference device's registers andmemories into other data similarly represented as physical quantitieswithin the conference device's memories or registers or other suchinformation storage, transmission or display devices.

Note the operations of the flow diagrams in FIGS. 2, 6, 8, 10, and 13are described with reference to the exemplary embodiment electronicdevices of FIGS. 14-16. However, it should be understood that theoperations of flow diagrams can be performed by embodiments of theinvention other than those discussed with reference to FIGS. 14-16, andthe embodiments discussed with reference to FIG. 14-16 can performoperations different than those discussed with reference to the flowdiagrams of FIGS. 2, 6, 8, 10, and 13.

While the flow diagrams in the figures herein above show a particularorder of operations performed by certain embodiments of the invention,it should be understood that such order is exemplary (e.g., alternativeembodiments may perform the operations in a different order, combinecertain operations, overlap certain operations, etc.).

While the invention has been described in terms of several embodiments,those skilled in the art will recognize that the invention is notlimited to the embodiments described, can be practiced with modificationand alteration within the spirit and scope of the appended claims. Thedescription is thus to be regarded as illustrative instead of limiting.

What is claimed is:
 1. A method implemented in an electronic deviceserving as a stream distributor distributing unicast video and audiostreams of a streaming platform system, the stream distributor receivinga unicast data flow containing data of a video and audio stream from aload balancer of the streaming platform system and distributing to oneor more workers of the streaming platform system to process, the unicastdata flow being transmitted in user datagram protocol (UDP) packets, themethod comprising: detecting initiation of a maintenance activity on avirtual machine or its host associated with the stream distributor,wherein the virtual machine is a part of a cloud computing environmentof the streaming platform system; indicating a failure mode of thestream distributor, wherein the failure mode indication is to cause theload balancer to switch the unicast data flow to an alternate streamdistributor; detecting a completion of the load balancer switching theunicast data flow to the alternate stream distributor; and halting thedistribution of the unicast data flow to the one or more workers.
 2. Themethod of claim 1, further comprising: delaying the maintenance activityfor a period of time after detecting the initiation, wherein the periodof time is to allow the load balancer to switch the unicast data flow tothe alternate stream distributor; and causing performance of themaintenance activity on the virtual machine or its host associated withthe stream distributor after the halting the distribution of the unicastdata flow to the one or more workers.
 3. The method of claim 2, whereinthe period of time ends upon the stream distributor no longer receivingUDP packets of the unicast data flow.
 4. The method of claim 2, whereindelaying the maintenance activity comprises interactions with anapplication programming interface (API) of the cloud computingenvironment.
 5. The method of claim 2, further comprising: aftercompletion of the maintenance activity, indicating that the streamdistributor is healthy again so that the load balancer switches theunicast data flow from the alternate stream distributor back to thestream distributor.
 6. The method of claim 1, wherein the load balancerprobes the stream distributor at a predetermined interval to determinewhether or not the stream distributor is in the failure mode.
 7. Themethod of claim 6, wherein upon determining the stream distributor is inthe failure mode, the load balancer switches the unicast data flow fromthe stream distributor to the alternate stream distributor.
 8. Themethod of claim 1, wherein the unicast data flow forwarded by the streamdistributor to the one or more workers is only a portion of a videosource entering the streaming platform system for processing, whereinthe portion of the video source is selected based at least partially onprocessing tasks executed by the one or more workers.
 9. An electronicdevice to serve as a stream distributor distributing unicast video andaudio streams of a streaming platform system, the stream distributorreceiving a unicast data flow containing data of the video and audiostream from a load balancer of the streaming platform system anddistributing to one or more workers of the streaming platform system toprocess, the unicast data flow being transmitted in user datagramprotocol (UDP) packets, the electronic device comprising: anon-transitory machine-readable storage medium to store the streamdistributor; and a processor coupled to the non-transitorymachine-readable storage medium, the processor to execute the streamdistributor, the stream distributor configured to detect initiation of amaintenance activity on a virtual machine or its host associated withthe stream distributor, wherein the virtual machine is a part of a cloudcomputing environment of the streaming platform system; indicate afailure mode of the stream distributor, wherein the failure modeindication is to cause the load balancer to switch the unicast data flowto an alternate stream distributor; detect a completion of the loadbalancer switching the unicast data flow to the alternate streamdistributor; and halt the distribution of the unicast data flow to theone or more workers.
 10. The electronic device of claim 9, wherein thestream distributor is further configured to: delay the maintenanceactivity for a period of time after detecting the initiation, whereinthe period of time is to allow the load balancer to switch the unicastdata flow to the alternate stream distributor; and cause performance ofthe maintenance activity on the virtual machine or its host associatedwith the stream distributor after the halting the distribution of theunicast data flow to the one or more workers.
 11. The electronic deviceof claim 10, wherein the stream distributor is further configured to:after completion of the maintenance activity, indicate that the streamdistributor is healthy again so that the load balancer switches theunicast data flow from the alternate stream distributor back to thestream distributor.
 12. The electronic device of claim 9, wherein theload balancer is to probe the stream distributor at a predeterminedinterval to determine whether or not the stream distributor is in thefailure mode.
 13. The electronic device of claim 9, wherein the unicastdata flow forwarded by the stream distributor to the one or more workersis only a portion of a video source entering the streaming platformsystem for processing, wherein the portion of the video source isselected based at least partially on processing tasks executed by theone or more workers.
 14. A non-transitory machine-readable medium havinginstructions stored therein, which when executed by a processor, causethe processor to perform operations in an electronic device serving as astream distributor distributing unicast video and audio streams of astreaming platform system, the stream distributor receiving a unicastdata flow containing data of a video and audio stream from a loadbalancer of the streaming platform system and distributing to one ormore workers of the streaming platform system to process, the unicastdata flow being transmitted in user datagram protocol (UDP) packets, theoperations comprising: detecting initiation of a maintenance activity ona virtual machine or its host associated with the stream distributor,wherein the virtual machine is a part of a cloud computing environmentof the streaming platform system; indicating a failure mode of thestream distributor, wherein the failure mode indication is to cause theload balancer to switch the unicast data flow to an alternate streamdistributor; detecting a completion of the load balancer switching theunicast data flow to the alternate stream distributor; and halting thedistribution of the unicast data flow to the one or more workers. 15.The non-transitory machine-readable medium of claim 14, wherein theoperations further comprise: delaying the maintenance activity for aperiod of time after detecting the initiation, wherein the period oftime is to allow the load balancer to switch the unicast data flow tothe alternate stream distributor; and causing performance of themaintenance activity on the virtual machine or its host associated withthe stream distributor after the halting the distribution of the unicastdata flow to the one or more workers.
 16. The non-transitorymachine-readable medium of claim 14, wherein delaying the maintenanceactivity comprises interactions with an application programminginterface (API) of the cloud computing environment.
 17. Thenon-transitory machine-readable medium of claim 14, wherein theoperations further comprise: after completion of the maintenanceactivity, indicating that the stream distributor is healthy again sothat the load balancer switches the unicast data flow from the alternatestream distributor back to the stream distributor.
 18. Thenon-transitory machine-readable medium of claim 14, wherein the loadbalancer probes the stream distributor at a predetermined interval todetermine whether or not the stream distributor is in the failure mode.19. The non-transitory machine-readable medium of claim 18, wherein upondetermining the stream distributor is in the failure mode, the loadbalancer switches the unicast data flow from the stream distributor tothe alternate stream distributor.
 20. The non-transitorymachine-readable medium of claim 14, wherein the unicast data flowforwarded by the stream distributor to the one or more workers is only aportion of a video source entering the streaming platform system forprocessing, wherein the portion of the video source is selected based atleast partially on processing tasks executed by the one or more workers.